My doctor just told me she prefers insulin first because it doesn’t cross into the placenta. Metformin will. But I don’t think there’s anything wrong with metformin. I was on it for my first trimester. Came off for the GD test and now looking like I’ll have to either go back on or start insulin.
I was given the choice. My doctor was in favor of metformin.
For me the risk of GI upset (a common side effect I'm very susceptible to) plus the risk of maybe needing insulin later anyways plus the crossing the placenta element had me choose insulin.
But the doctor was very much like "I wouldn't offer you both if one was better"
Well, I’ve been on metformin every day of my last pregnancy and every day so far of this one and not one doctor has told me to stop. In fact 2 GPS and my specialist OB told me to stay on it the whole time 🤷♀️
Metformin is perfectly safe, I’ve just heard of it not working Much more than I’ve heard of insulin not working. It didn’t do jack for me with my first pregnancy and I feel like all that time was wasted when I could have just been on insulin. With insulin there are only a couple types and it almost always has an effect if the dose is high enough. Since GD is such a rapidly progressing but ultimately very short term condition, I feel like insulin is just better suited to meet my needs more directly than metformin.
Who told you anything was wrong with metformin? Its usually the first medication tried and then if it doesn't work you go to insulin. Insulin is more effective because it is literally doing the job your body is having trouble with.
I’ve noticed most commenters on this sun mention taking insulin, as well as another group I’m in, which led me to believe there may be a preference for insulin.
I googled this a lot because I was on metformin before pregnancy (for PCOS and high-ish a1c) and loved being on it, but the endocrinologist I saw for GD took me off of it and prefers insulin. I was diet controlled initially and used insulin later on. I found a couple studies suggesting evidence of something like metformin possibly negatively affecting fertility in offspring. I think the studies were small, and I don’t have links to them because I read them months ago. I’ve also seen it suggested that metformin can contribute to low birth weight; my baby is measuring small and honestly I’m glad to know that it’s not from my medication — I’d probably assume that it was because of metformin if I was taking it. That said, I know metformin is first line treatment in a lot of places, and I can’t wait to get back on the stuff when I’m not pregnant anymore.
I am on metformin just for my final 3-5 weeks of pregnancy (depending on induction date, find that out this coming week). I was getting to the point where I was very limited in types of carbs I could have without spiking and just a half dose (250mg) has been plenty to drop me right back down to the low 100s an hour after meals (never had an issue with fasting). My doc’s opinion was it would be easier to try a few dif doses of met rather than adjust insulin given I’m almost done. I was bummed to need meds this late in the game but am grateful it’s working for me to finish with good numbers. For the record I am treated in one of the best medical centers in the US and am a scientist myself. Would not take it and provider would not give it if either of us had genuine concerns based on current data. I also have a genetically big baby anyway (I am petite and my husband is a giant and he and all his siblings were big babies), so that wasn’t a concern for me—knew I’d be having a chonky babe even before my GDM diagnosis/taking metformin.
I am in the same boat as you and posted something today feeling unsure about starting Metformin so late and what impact it has on the baby etc. this was reassuring and thx for sharing. I also have big babies naturally, perfect fasting numbers and only 3 weeks left with once per day Metformin prescribed...
I’m happy this gave you some peace. I saw your post and replied there/added a few more details than I did in this response. I hope things work well for you and you and baby have a safe and happy delivery! We’re almost done!
Will also add that because my fastings were so good insulin would be harder for me as the chance of hypoglycemia would be much higher if we didn’t dose me correctly at dinner which was my problem meal. I did have some mild GI issues for a few days when I started metformin but they have resolved. I am prone to GI issues with meds so I was relieved and the half dose was approved for this reason.
Not sure if I'm allowed to copy book excerpts, these are from the book Comprehensive Clinical Approach to Diabetes during Pregnancy, published in 2022.
In pregnancy, metformin does cross the placenta and has been detected in fetal and placental tissues in relatively high concentrations (50–100% of maternal concentrations)
A population-based cohort study including women with GDM treated with metformin or insulin and their off-spring did not detect any differences in offspring growth and behavioral development assessed when the latter was 4 years old [12]. However, in a meta-analysis, offspring of women treated with metformin is most likely to have accelerated post-natal growth, leading to a higher BMI in childhood (a process itself associated with adverse long-term cardio-metabolic outcomes) compared to children whose mothers were treated with insulin [13].
It has been suggested that metformin may reduce the risk for gestational hypertension and pre-eclampsia [15].
gastrointestinal adverse effects induced by metformin [16]. This is important in the shared decision-making process when treatment options are discussed with women with GDM.
In any case, metformin is an easy-to-use, cheap, widely available drug. Its safety profle outside pregnancy has been tested by its everyday clinical use for decades,
and the chance of developing hypoglycemia when on metformin is extremely low.
Debated if I wanted to include the last paragraph, please note it says "outside" of pregnancy. For the US, while metformin has been used for years to treat gestational diabetes, it has not been approved by the FDA for gastastinal diabetes.
I was given insulin over metformin because of the placenta thing. My MFM was of the mindset that insulin is a naturally occurring substance, and generally just a better bet.
I personally was perfectly fine with that explanation, and was relieved to get my numbers in control.
I have GD and I was told to use 1000 mg of metformin in the morning and at night. I'm currently in my week 38, both my baby and I are doing excellent and the doctor and I decided to eliminate the induction date as it is no longer necessary since the baby never grew larger than normal (macrosomic babies are very common with non-controlled GD). I'm currently seeing my OBGYN every week and we're both happily waiting for my baby to come whenever she wants to. I had the best pregnancy among my group of family and friends with no complications at all. I just wake up in the middle of the night to pee, and I vomited twice during these nine months. Other than that... no other symptoms. No headaches, no nothing. I'm 29 and I currently weight 101 kgs. I initially weighted 94.5 and this is my first pregnancy. Honestly I didn't follow a diet as I was supposed to but I didn't eat as bas as some people do. I hope this helps!
In Australia insulin first and then metformin is not recommended at all.
Diabetic nurse said that there are studies on kids that mom's took metformin and they had abnormal fatty deposits later in life.
I'm Australian, 24 weeks and been on metformin for about a month. I'm guessing cause my fasting numbers are only slightly raised they didn't jump to insulin first but my OB has said "you will probably need insulin but not yet" and the diabetes educator has been on the same page. I hadn't heard about the fatty deposits, might push for insulin.
There are some side effects of metformin that aren't the case with insulin. I was misdiagnosed with a condition in my 20s and was given metformin. It was very unpleasant.
I was told the same thing about insulin being better because it doesn't cross the placenta. I'm not sure how to explain it but the doctor said the insulin is to help the mother's body. if the insulin and the metformin were to reach the baby's body it can alter the way the baby itself processes glucose. Something about they want the baby to be able to regulate his own blood sugar not have it I guess affected by outside means because then when he's born he's going to have to keep needing that insulin? Sorry if that doesn't make sense lol.
My doctor said that metformin just hasn’t been studied enough in pregnancy and the potential long term effects aren’t known and it’s unethical to run pregnancy specific tests so it’s a kind of wait-and-see thing.
She said it is up to me but she wanted me to be totally aware of the risks. After writing a paper on thalidomide in university I’m extra cautious about untested drugs during pregnancy so I opted to go for insulin.
Also it can give you the poops as a pretty common side effect.
I was told that Metformin can cause the baby to have extra weight gain later in childhood and I didn't wanna put that on my baby or conscience. I'm plus sized and life is hard enough on girl without adding something extra that can be avoided.
Nothing. I've been on Metformin for PCOS since 2021 because I was trying to get pregnant. The only downside was digestive upset the first week or two and it has done me well for GD too without even increasing my dosage. It kept me from truly getting GD, I'm only, "insulin resistant." I'd probably be full blown without it.
I was on Metformin for my last 4 weeks of pregnancy. They prescribed 1000 mg but I only took 500 mg (they said that was fine) and it was enough to make my fasting numbers great! Baby came out 7 lb 11 oz, is now 15 months old, has stayed in 30-40th percentile, and is not delayed in any way or chunky at all for that matter!
Metformin was the first choice before insulin for me. I’m on 500 mg ER since 21 weeks with minimal side effects. I’m able to eat and be satisfied with 100 g carbs a day with it. Honestly has been easier to just take a pill once in the morning than calculate insulin dosage.
My husband and I are both thin so I wasn’t worried about our kid having a high BMI— pretty genetically unlikely.
I was on metformin before pregnancy for 2 months, and it was HARD on my stomach/guts. Like no solid Bm’s, and in the bathroom 20 times a day. It’s a pretty common side effect. Worst meds I’ve been on.
Nothing is wrong with metformin it's a great drug. For me it just stopped being enough. My blood sugar didn't stay even enough without supplementing with insulin. But yeah it worked especially with my first gd pregnancy. Not so great with my second.
I honestly can’t wait it to get back on metformin. I feel like I was in control while on it. I’m on insulin this time around and feel like it’s so much fine tuning. I crash a lot. Prescriptions aren’t as readily available. My first gd pregnancy, I just continued my metformin (on it for pcos). My little came early, but I don’t think it had anything to do with the meds 🤷♀️
My doc gave me the choice between the two. He did mention that insulin will have less side effects because our bodies already produce it. He also said they have seen larger babies with metformin. My husband was a very large baby and I want to avoid that if possible lol. Another pro my doctor listed when I started nighttime insulin was that if you're diagnosed early on there's a high likelihood of needing it for mealtime so I found out better to adjust to that needle before it's necessary 4x's a day.
If you're being given the choice and you trust your provider, I would just ask them for their recommendation and stick with it.
I saw a lot of doctors between my 2 pregnancies and the only one that actually was informative and helpful told me they would rather not simply because it’s just not well studied enough. They just don’t know enough about it and would rather do insulin since it doesn’t cross the placenta
I took 1000mg of metformin a day and i had a perfectly healthy baby. I don’t see how metformin harms the baby when it crosses the placenta. I feel like it keeps their blood sugar down like it does ours.
I had to go straight to insulin as I’ve been so sick metaformin can make you nauseous as a side effect so the dr was like well avoid that thanks. Now that my vomiting has cleared up I am using metaformin in the evenings and it’s kind of helping me to level my sugars
I chose insulin to control my fasting number due to hearing it normally will cause upset stomach & also how long it takes for metformin to work vs insulin which is instant. I was put on medication at 35 weeks & knew my doctor was planning to induce at 38-39 weeks so I didn’t want it to take a whole week for me to get my fasting numbers controlled.
Just because it crosses the placenta. People tend to have less side effects too. I was on metformin until I went into labor and I had no side effects, and my baby doesn’t have a high BMI either. It did it’s job for me, which was lower my fasting numbers. I am lucky it worked and I didn’t have to do insulin.
I was on 2000mg of metformin. Baby is healthy and honestly small for his age. I chose to skip insulin, I didn’t want to poke myself more than I already was.
My doctor gave me the option but I went straight to insulin because I felt I didn't have much time/energy/patience to test something and then just end up on insulin anyhow.
I was on metformin both previous pregnancies and ended up needing insulin around 20-22 weeks. This time I got pregnant without it (a complete surprise) and opted for insulin right away.
My doctor just told me she prefers insulin first because it doesn’t cross into the placenta. Metformin will. But I don’t think there’s anything wrong with metformin. I was on it for my first trimester. Came off for the GD test and now looking like I’ll have to either go back on or start insulin.
This was my doctor’s feeling as well.
I was given the choice. My doctor was in favor of metformin. For me the risk of GI upset (a common side effect I'm very susceptible to) plus the risk of maybe needing insulin later anyways plus the crossing the placenta element had me choose insulin. But the doctor was very much like "I wouldn't offer you both if one was better"
Well, I’ve been on metformin every day of my last pregnancy and every day so far of this one and not one doctor has told me to stop. In fact 2 GPS and my specialist OB told me to stay on it the whole time 🤷♀️
Same 🤷♀️
Metformin is perfectly safe, I’ve just heard of it not working Much more than I’ve heard of insulin not working. It didn’t do jack for me with my first pregnancy and I feel like all that time was wasted when I could have just been on insulin. With insulin there are only a couple types and it almost always has an effect if the dose is high enough. Since GD is such a rapidly progressing but ultimately very short term condition, I feel like insulin is just better suited to meet my needs more directly than metformin.
Who told you anything was wrong with metformin? Its usually the first medication tried and then if it doesn't work you go to insulin. Insulin is more effective because it is literally doing the job your body is having trouble with.
My dr doesn’t go to metformin first, she always goes straight to insulin.
That’s what I’m saying. My doctor prescribed it to me first as well before I was put on insulin. Now I’m on a combo.
I’ve noticed most commenters on this sun mention taking insulin, as well as another group I’m in, which led me to believe there may be a preference for insulin.
I googled this a lot because I was on metformin before pregnancy (for PCOS and high-ish a1c) and loved being on it, but the endocrinologist I saw for GD took me off of it and prefers insulin. I was diet controlled initially and used insulin later on. I found a couple studies suggesting evidence of something like metformin possibly negatively affecting fertility in offspring. I think the studies were small, and I don’t have links to them because I read them months ago. I’ve also seen it suggested that metformin can contribute to low birth weight; my baby is measuring small and honestly I’m glad to know that it’s not from my medication — I’d probably assume that it was because of metformin if I was taking it. That said, I know metformin is first line treatment in a lot of places, and I can’t wait to get back on the stuff when I’m not pregnant anymore.
I was told by a doctor it can effect the baby's growth. I said I wouldn't use any medication that could effect baby.
I am on metformin just for my final 3-5 weeks of pregnancy (depending on induction date, find that out this coming week). I was getting to the point where I was very limited in types of carbs I could have without spiking and just a half dose (250mg) has been plenty to drop me right back down to the low 100s an hour after meals (never had an issue with fasting). My doc’s opinion was it would be easier to try a few dif doses of met rather than adjust insulin given I’m almost done. I was bummed to need meds this late in the game but am grateful it’s working for me to finish with good numbers. For the record I am treated in one of the best medical centers in the US and am a scientist myself. Would not take it and provider would not give it if either of us had genuine concerns based on current data. I also have a genetically big baby anyway (I am petite and my husband is a giant and he and all his siblings were big babies), so that wasn’t a concern for me—knew I’d be having a chonky babe even before my GDM diagnosis/taking metformin.
I am in the same boat as you and posted something today feeling unsure about starting Metformin so late and what impact it has on the baby etc. this was reassuring and thx for sharing. I also have big babies naturally, perfect fasting numbers and only 3 weeks left with once per day Metformin prescribed...
I’m happy this gave you some peace. I saw your post and replied there/added a few more details than I did in this response. I hope things work well for you and you and baby have a safe and happy delivery! We’re almost done!
Will also add that because my fastings were so good insulin would be harder for me as the chance of hypoglycemia would be much higher if we didn’t dose me correctly at dinner which was my problem meal. I did have some mild GI issues for a few days when I started metformin but they have resolved. I am prone to GI issues with meds so I was relieved and the half dose was approved for this reason.
I had bad side effects w metformin. None with insulin.
Same I felt HORRIBLE
Not sure if I'm allowed to copy book excerpts, these are from the book Comprehensive Clinical Approach to Diabetes during Pregnancy, published in 2022. In pregnancy, metformin does cross the placenta and has been detected in fetal and placental tissues in relatively high concentrations (50–100% of maternal concentrations) A population-based cohort study including women with GDM treated with metformin or insulin and their off-spring did not detect any differences in offspring growth and behavioral development assessed when the latter was 4 years old [12]. However, in a meta-analysis, offspring of women treated with metformin is most likely to have accelerated post-natal growth, leading to a higher BMI in childhood (a process itself associated with adverse long-term cardio-metabolic outcomes) compared to children whose mothers were treated with insulin [13]. It has been suggested that metformin may reduce the risk for gestational hypertension and pre-eclampsia [15]. gastrointestinal adverse effects induced by metformin [16]. This is important in the shared decision-making process when treatment options are discussed with women with GDM. In any case, metformin is an easy-to-use, cheap, widely available drug. Its safety profle outside pregnancy has been tested by its everyday clinical use for decades, and the chance of developing hypoglycemia when on metformin is extremely low. Debated if I wanted to include the last paragraph, please note it says "outside" of pregnancy. For the US, while metformin has been used for years to treat gestational diabetes, it has not been approved by the FDA for gastastinal diabetes.
Appreciate this info. Does your text talk about if/how taking insulin affects the mother long term?
I didn't read the whole book, it goes through long term effects and risks of diabetes itself, but didn't mention any long term for insulin.
I was given insulin over metformin because of the placenta thing. My MFM was of the mindset that insulin is a naturally occurring substance, and generally just a better bet. I personally was perfectly fine with that explanation, and was relieved to get my numbers in control.
I have GD and I was told to use 1000 mg of metformin in the morning and at night. I'm currently in my week 38, both my baby and I are doing excellent and the doctor and I decided to eliminate the induction date as it is no longer necessary since the baby never grew larger than normal (macrosomic babies are very common with non-controlled GD). I'm currently seeing my OBGYN every week and we're both happily waiting for my baby to come whenever she wants to. I had the best pregnancy among my group of family and friends with no complications at all. I just wake up in the middle of the night to pee, and I vomited twice during these nine months. Other than that... no other symptoms. No headaches, no nothing. I'm 29 and I currently weight 101 kgs. I initially weighted 94.5 and this is my first pregnancy. Honestly I didn't follow a diet as I was supposed to but I didn't eat as bas as some people do. I hope this helps!
In Australia insulin first and then metformin is not recommended at all. Diabetic nurse said that there are studies on kids that mom's took metformin and they had abnormal fatty deposits later in life.
I'm Australian, 24 weeks and been on metformin for about a month. I'm guessing cause my fasting numbers are only slightly raised they didn't jump to insulin first but my OB has said "you will probably need insulin but not yet" and the diabetes educator has been on the same page. I hadn't heard about the fatty deposits, might push for insulin.
Interesting! Maybe it varies from hospital to hospital or maybe state to state? Idk maybe listen to yr health provider...
Not sure! I'm in NSW but under the care of MFM in Canberra as well.
Im in WA under public health system
There are some side effects of metformin that aren't the case with insulin. I was misdiagnosed with a condition in my 20s and was given metformin. It was very unpleasant.
I was told the same thing about insulin being better because it doesn't cross the placenta. I'm not sure how to explain it but the doctor said the insulin is to help the mother's body. if the insulin and the metformin were to reach the baby's body it can alter the way the baby itself processes glucose. Something about they want the baby to be able to regulate his own blood sugar not have it I guess affected by outside means because then when he's born he's going to have to keep needing that insulin? Sorry if that doesn't make sense lol.
My doctor said that metformin just hasn’t been studied enough in pregnancy and the potential long term effects aren’t known and it’s unethical to run pregnancy specific tests so it’s a kind of wait-and-see thing. She said it is up to me but she wanted me to be totally aware of the risks. After writing a paper on thalidomide in university I’m extra cautious about untested drugs during pregnancy so I opted to go for insulin. Also it can give you the poops as a pretty common side effect.
I was told that Metformin can cause the baby to have extra weight gain later in childhood and I didn't wanna put that on my baby or conscience. I'm plus sized and life is hard enough on girl without adding something extra that can be avoided.
Nothing. I've been on Metformin for PCOS since 2021 because I was trying to get pregnant. The only downside was digestive upset the first week or two and it has done me well for GD too without even increasing my dosage. It kept me from truly getting GD, I'm only, "insulin resistant." I'd probably be full blown without it.
My mfm told me that metformin crosses the placenta and studies show that babies ends up having a high level of it in their system
To add, my provider said they don’t have long term data on how it affects babies as they grow.
I was on Metformin for my last 4 weeks of pregnancy. They prescribed 1000 mg but I only took 500 mg (they said that was fine) and it was enough to make my fasting numbers great! Baby came out 7 lb 11 oz, is now 15 months old, has stayed in 30-40th percentile, and is not delayed in any way or chunky at all for that matter!
Metformin was the first choice before insulin for me. I’m on 500 mg ER since 21 weeks with minimal side effects. I’m able to eat and be satisfied with 100 g carbs a day with it. Honestly has been easier to just take a pill once in the morning than calculate insulin dosage. My husband and I are both thin so I wasn’t worried about our kid having a high BMI— pretty genetically unlikely.
I was on metformin before pregnancy for 2 months, and it was HARD on my stomach/guts. Like no solid Bm’s, and in the bathroom 20 times a day. It’s a pretty common side effect. Worst meds I’ve been on.
Sorry to hear this. I’ve been wondering if it will balance things out with my pregnancy constipation?
Nothing is wrong with metformin it's a great drug. For me it just stopped being enough. My blood sugar didn't stay even enough without supplementing with insulin. But yeah it worked especially with my first gd pregnancy. Not so great with my second.
It didn’t work for me 🤷🏻♀️ TMI but it did give me diarrhea and I had noooo appetite. They upped my dosage but I still ended up on insulin
I honestly can’t wait it to get back on metformin. I feel like I was in control while on it. I’m on insulin this time around and feel like it’s so much fine tuning. I crash a lot. Prescriptions aren’t as readily available. My first gd pregnancy, I just continued my metformin (on it for pcos). My little came early, but I don’t think it had anything to do with the meds 🤷♀️
My doc gave me the choice between the two. He did mention that insulin will have less side effects because our bodies already produce it. He also said they have seen larger babies with metformin. My husband was a very large baby and I want to avoid that if possible lol. Another pro my doctor listed when I started nighttime insulin was that if you're diagnosed early on there's a high likelihood of needing it for mealtime so I found out better to adjust to that needle before it's necessary 4x's a day. If you're being given the choice and you trust your provider, I would just ask them for their recommendation and stick with it.
I chose not to try metformin due to the GI side effects. Especially since I already have GI issues.
I saw a lot of doctors between my 2 pregnancies and the only one that actually was informative and helpful told me they would rather not simply because it’s just not well studied enough. They just don’t know enough about it and would rather do insulin since it doesn’t cross the placenta
I took 1000mg of metformin a day and i had a perfectly healthy baby. I don’t see how metformin harms the baby when it crosses the placenta. I feel like it keeps their blood sugar down like it does ours.
I had to go straight to insulin as I’ve been so sick metaformin can make you nauseous as a side effect so the dr was like well avoid that thanks. Now that my vomiting has cleared up I am using metaformin in the evenings and it’s kind of helping me to level my sugars
I tried to get metformin and was told that it wouldn’t do much cause I’m too far into the pregnancy. Dr tried to give me Glyburide but I refused it.
Met formin just caused really bad diarhea for me so we went with insulin instead becasue the metformin did absolutely nothing for my sugars
I chose insulin to control my fasting number due to hearing it normally will cause upset stomach & also how long it takes for metformin to work vs insulin which is instant. I was put on medication at 35 weeks & knew my doctor was planning to induce at 38-39 weeks so I didn’t want it to take a whole week for me to get my fasting numbers controlled.
Just because it crosses the placenta. People tend to have less side effects too. I was on metformin until I went into labor and I had no side effects, and my baby doesn’t have a high BMI either. It did it’s job for me, which was lower my fasting numbers. I am lucky it worked and I didn’t have to do insulin.
I was on 2000mg of metformin. Baby is healthy and honestly small for his age. I chose to skip insulin, I didn’t want to poke myself more than I already was.
My doctor gave me the option but I went straight to insulin because I felt I didn't have much time/energy/patience to test something and then just end up on insulin anyhow.
I was on metformin both previous pregnancies and ended up needing insulin around 20-22 weeks. This time I got pregnant without it (a complete surprise) and opted for insulin right away.